Method of preventing wall action



H. F. SMITH.

METHOD OF PREVENTING WALL ACTION, APPLICATION FILED MAY 24, 1918.

1,417,636 Patented May 30,1922;

2 sHEETs-sHEET 1.

H. F, SMlTHf METHOD OF PREVENTING WALL ACTION APPLICATION FILED MAY 24, 1918.

1 ,4 1 7, 63 6 Patented May 30, 1922..

2 SHEETS-SHEET 2.

UNITED STATES PATENT gormca.

HARRY 1*. SMITH, or 'DAYTON, HI0, ASSIGNOR, BY- MESNE AssIeNMEnrs in THE GAS RESEARCH COMPANY, or DAYTON, 01110, -'A CORPORATION o 2,

"mansion on PREVENTING WALL ACTION.

Specification of Letters iatent. Patented '30, 1922 Application filed illtay 24, 1918. Serial No. 236,263.-

To all whom it may cmecem:

Be it known that I, HARRY 5 and State of Ohio, have invented certain new and useful Improvements in Methods of Preventing Wall Action, of whichthe following is a .full, clear, and exact description. This invention relates to gas producers and more particularly to. the prevention of wall action therein. l

In the operation 'of gas producers there is' a decided tendency for a portionof the air blast to pass upwardly along the lining ofthe generating chamber andthrough ad-.

'jacent layers of the fuel bed more freely than through the body of the fuel bed. I There is also a tendency for the fuel bed to shrink away from the lining of the pro-- ducer as the volatilecomponents of the fuel are driven off, which permits of 'an even i more ready flow of air blast adjacent the lining. Where .such' freer flow of a11- blast occurs the rate of combustion w1ll be greater than the rate of combustion in the body of the fuel bed. This gives rise to channels or chimneys in the fuel bed which-permit -the flow of considerable quantities of air blast therethrough without such air coming into intimate contact with the incandescent fuel. As a result, some part of the air blast will passthrough the fuel bed without combining with the carbonaceous Simaterial thereof. Such portion of un-, acted upon air blast will either unite with,

the combustible gas in the upper part of the generating chamber to formjcarbon dioxideor will pass\unchan'ged into the: delivery 40 main where it will act as a diluent to cut down the heat value of the gas. This condition is known as wall action; v

- Wall action is especially troublesome in 'gas roducers of large size where, because of the considerable grate area, it is more difficult to secure uniform distribution of the air blast and uniform consistency in the fuel bed. The object of the present invention is to prevent this wall action by causing the air blast to pass .through the body of the fuel bed, while at the same time keeping the temperature of the layer of fuel immediately adjacent the lining v comparatively low, .thus preventing the burning of channels or chimneys therein [even gh some" part of the air blast FVSMrrH, a citizen of the United States of America, residing at Dayton, county of Montgomery,

should pass upwardly In carrying this inventionyinto effect, an

gen-

or inactive, gas or vapor thefainblast is deflected towardthe center of'the fuel bed which of itself will prevent the formation of channels or chimneys adjacent the outer 'edgesthereof. Further, the presence of thisinert, or inactive, blanket will tend to keep I the temperature of that particular portion of the f'ueI bed in which it exists, comparatively low, sov that the development of excessive temperatures, which are]; present Where such channels or chimneys are burned in the fuelbed, are prevented.

-In the drawing in which like characters of reference designate like parts throughout .the several views thereof,

Fig. lis a sectionaljview, along 'the line 1-1 of Fig. 2, through a producer illustrating an embodiment of a preferred ferm of apparatus for carrying effect; v Fig. 2 is a sectional view through the ap'- is 'inventiominto paratus illustrated in Fig. 1, along the line,

2-2 thereof;

'Fig. 3 is a sectional view, along the line 33 of Fig. 4, of a modifiedform of apparatus for. carrying this invention into effect; and

Fig. 4 is a sectional view, along line 4- 4 of the apparatus illustrated in .Fig. 3.

In the drawing, 1 designates the shell of a-producer which may be of any conventional design. Inside of shell 1 is a lining 2 of fire brick or similar material. cated near the bottom of the producer is a grate 3 for supporting the fuel bed, and carried at the top of the producer is a fuel feeding device 4. Opening into the producer adjacent the bottom thereof is an air inlet port 5", so positioned that the air or .other gas introducedtherethrough will enter the interior. of the producer below the grate. pass upwardly through the grate and fuel bed supported thereby, and then outwardly through the ofi'take main 6. It is the gen eral producer practice to introduce a mixture of air and moisture into the generating chamber forreaction with the fuel bed there- ,in' 'to produce a combustible gas.

The term air blast is used herein to designate gen-' erally this mixture of air and moisture, whether that blast be introduced under pressure or under suction. The producer thus described is of a conventional, suction-operating type.

Near the bottom of the producer lining 1s a zone of metallic brick 7. As illustrated, this zone of metallic brick consists of hollow brick so formed that, when laid in position, the hollow spaces-Y herein form a continuous manifold 8 extending completely around the producer as clearly illustrated in Fig. 2. Leading through the wall of the producer and opening into this manifold 8 are a pluyrality of pipes 9 adapted to admit steam, ex-

. interior of the manifold 8 with the interior of the generating chamber of the producer. With this structure it is obvious that if steam or other relatively inert, or inactive gas or vapor, is introduced into the manifold 8 through the pipes 9 under, a pressure preponderating slightly over the pressure existing in the generating chamber, such gas or vapor will pass, through the numerous passages 10, will be deflected and carried upwardly by the current of ascending gases within the chamber, and will tend to form a blanket along the lining of the generating chamber which will prevent too ready upward passage of the air blast through the fuel bed immediately adjacent the'said lining. In addition, any tendency toward unduly rapid combustion of the fuel adjacent the lining will beprevented by the relatively inactive gas orvapor. And this of itself will effectively prevent the formation of chimneys or channels, since these can be formed only where the rate of combustion is comparatively too rapid.

It is obvious that hollow brick made of some material other than metal may be substituted for the metal brick 7. It is also ob- 'vious that the manifold 8 need not neces sarily be located within theproducer shell. It is quite feasible to entirely dispense with the zone of metallic brick 7 and simply provide a steam manifold extending completely around: the outside of the producer shell and connected with the interior of the generating chamber by means of a plurality of pipes whoseinner ends'terminate adjacent the inner surface of the producer lining. In Fig. 3 is illustrated a-difli'erent form of apparatus for carrying this method into effect. In the apparatus illustrated thereinfire brick, composed of the same material as the rest of the lining, but so arranged that when in place there will be two vertical passages 11 extending downwardly along the '70 .tion, however, I have inserted two layers of producer shell to the zone of metallic brick 12. The metallic brick 12 are similar in structure to the brick 7 of Fig. 1, in that they have, when in place, the same manifold 8 running therethrough and the same passages 10. Several of the'brick constituting this zone, however, have an additional passage-Way 13 adapted, when the brick are laid in position, to register with the passages 11 and connect those passages with the manifold 8.

Connecting the top of the passages 11 with the interior of the generating chamber are two radial passages 14. Passing through the top of the producer shell and into the passages 11 are two steam pipes15, the inner ends of which carry steam nozzles 16 which terminate adjacent thepassages 14,

the arrangement being such that the nozzles 16, passages 14, and passages 11 constitute in effect ejectors for drawing gas from the gencrating chamber and forcing such gas along the passages 11 into the manifold 8, and then through the passages 10 back into the in-" terior of the generating chamber. Located in each of the pipes 15 is a control valve 17,

.by means of which the eject-or action. may be rior of the generating chamber wherein the mixed gas and vapor will spread out along the lining of the producer to form a deadenlng blanket, in the same manner as described in connection with Fig. 1.

A number of different kinds of gas or vapor maybe used advantageously in carrying this invention into efi'ect. I have found from experiment, however, that steam when used alone, seems to give the most satisfac tory results. Not only does steam form a blanket along the lining of the producer which deflects the air blast toward the interior of the generating chamber where it passes through the body of the fuel bed, but it has a quenching action which lowers the temperature of the fuel bed adjacent the lining, so that undue consumption of the fuel in this vzone is obviated and the formation of the channels is thereby efl'ectively prevented.

It is evident that any other gas or vapor tending to prevent undue combustion of those portions of the fuel bed covered by it will have practically this same effect. This would be true in the case of engine exhaust gases in which the presence of large quantities of carbon dioxide would tend to make the development of excessive temperatures impossible. It has also been found that a mixture of producer gas and steam, such as could be fed-into the generating chamber in the type of apparatus illustrated in Fig. 3 has about this same effect, since the producer gas itself is not capable of sustaining combustion in the fuel bed, although it can of course burn in the presence of atmospheric air, and in addition, the steam carried therein tends to exercise a quenching action as described above.

While the methods herein described, and the forms of apparatus for carrying those methods into effect, constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to.

these precise methods and forms of apparatus, and that changes may be made in either without departing from the scope of the invention which is defined in theappended claims.

What I claim as new and desire to secure by Letters Patent is: i

1. The method of generating producer gas, in which a fuel bed of ignited carbonaceous material is maintained within the generating chamber of the producer, which consists in blasting the body portion of the fuel bed within the generator with a fluid adapted to react with the fuel. to form a combustible gas, and at the same time passing through the zone of fuel adjacent the wall of the generator suflicient of a fluid which is relatively inactive with respect to the fuel to exclude from such zone substantially all of the relatively active fluid which is being passed through the body of the fuel bed.

2. The method of generating gas in a gas producer which consists in maintaining a fuel bed of carbonaceous material within the producer; passing a mixture of .air and steam through the body of such fuel bed, to generate a combustible gas; and at the same time maintaining a blanket of a fluid incapable of sustaining combustion within the zone of the fuel bed adjacent the wall of the producer to substantially prevent the combustion of the fuel within said zone.

3. The method of generating gas in a gas producer which consists in maintaining a fueld bed of carbonaceous material within the pro ucer; passin throu h the body porti n of the fuel bed g g Q sustaining combustion of the fuel, to cause the generation of combustible gas; and at thesame timepassing through the zone of fuel adjacent the wall of the producer a fluid hich is incapable of sustaining combustion of the fuel.

4. The method of generating gas in a gas producer which consists in maintaining a fuel bed of carbonaceous material Within the producer; passing through the body portion of the fuel bed a fluid which is adapted to sustain combustion of the fuel, to cause the generation of combustible gas within saidbed; and at the same time maintaining within'thezone of fuel adjacentthe wall of the producer a blanket of fluid which is incapable of sustaining combustion of the fuel in the fuel bed; the said blanket being such as to deflect towards the center of the fuel bed the fluid adapted to sustain combustion therein.

a fluid-which is capable of 5. The method of preventing wall action in a gas producer which consists in withdrawing a portion of the gas from above the fuel bed, mixing it with a non-combustible fluid, and introducing the mixture into the fuel bed in such wise as to form a blanket of the mixed gas and non-combustiblefluid within the zone of fuel adjacent the walls of i said producer.

In testimony whereof I aflix my signature.

HARRY F. SMITH. Witnesses: WM. W. EARHART, R. M. CHATTERTON. 

